ヒト軟骨細胞由来三次元培養組織の軟骨再分化に及ぼす繰り返し圧縮負荷刺激の効果

Mechanical stress causes cartilage destruction in the temporomandibular joint (TMJ) and dedifferentiation of chondrocytes in TMJ cartilage. Although dedifferentiated chondrocytes redifferentiate in vitro under certain culture conditions with growth factors such as BMPs and TGF-β or mechanical loading, the effect of mechanical stress on redifferentiation of chondrocytes is unclear. We attempted to elucidate the effect of cyclic compressive loading on the redifferentiation of dedifferentiated human chondrocytes in three-dimensional (3D) culture. Our hypothesis was that cyclic compressive loads alter gene expression in an early stage of cartilage redifferentiation. Dedifferentiated human chondrocytes in monolayer were seeded onto a collagen scaffold to produce 3D tissue and were cultured with BMP-2 (500 ng/ml) and TGF-β3 (10 ng/ml) for 28 days. The effect of cyclic compressive loading of 20kPa at 0.5 Hz for 1 hour per day on the 3D tissue was analyzed for Sox9, BMP2, Aggrecan and type II collagen gene expressions on days 1, 4 and 7. Three-dimensional constructs with BMP-2 and TGF-β3 exhibited positive Safranin O staining on day 28. mRNA expression levels of Sox9 and Aggrecan gene were upregulated on day 4 with BMP-2 and TGF-β3, and type II collagen gene expression was also upregulated on day 7. Cyclic compressive loading on the 3D constructs further upregulated Sox9 and BMP2 gene expression on day 4, and BMP2 gene expression was also upregulated on day 7. We concluded that cyclic compressive loading alters gene expression during the early stage of cartilage redifferentiation.大阪歯科大学2016年